1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Hisilicon's Hi6220 mailbox driver
4 *
5 * Copyright (c) 2015 HiSilicon Limited.
6 * Copyright (c) 2015 Linaro Limited.
7 *
8 * Author: Leo Yan <leo.yan@linaro.org>
9 */
10
11 #include <linux/device.h>
12 #include <linux/err.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/kfifo.h>
16 #include <linux/mailbox_controller.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21
22 #define MBOX_CHAN_MAX 32
23
24 #define MBOX_TX 0x1
25
26 /* Mailbox message length: 8 words */
27 #define MBOX_MSG_LEN 8
28
29 /* Mailbox Registers */
30 #define MBOX_OFF(m) (0x40 * (m))
31 #define MBOX_MODE_REG(m) (MBOX_OFF(m) + 0x0)
32 #define MBOX_DATA_REG(m) (MBOX_OFF(m) + 0x4)
33
34 #define MBOX_STATE_MASK (0xF << 4)
35 #define MBOX_STATE_IDLE (0x1 << 4)
36 #define MBOX_STATE_TX (0x2 << 4)
37 #define MBOX_STATE_RX (0x4 << 4)
38 #define MBOX_STATE_ACK (0x8 << 4)
39 #define MBOX_ACK_CONFIG_MASK (0x1 << 0)
40 #define MBOX_ACK_AUTOMATIC (0x1 << 0)
41 #define MBOX_ACK_IRQ (0x0 << 0)
42
43 /* IPC registers */
44 #define ACK_INT_RAW_REG(i) ((i) + 0x400)
45 #define ACK_INT_MSK_REG(i) ((i) + 0x404)
46 #define ACK_INT_STAT_REG(i) ((i) + 0x408)
47 #define ACK_INT_CLR_REG(i) ((i) + 0x40c)
48 #define ACK_INT_ENA_REG(i) ((i) + 0x500)
49 #define ACK_INT_DIS_REG(i) ((i) + 0x504)
50 #define DST_INT_RAW_REG(i) ((i) + 0x420)
51
52
53 struct hi6220_mbox_chan {
54
55 /*
56 * Description for channel's hardware info:
57 * - direction: tx or rx
58 * - dst irq: peer core's irq number
59 * - ack irq: local irq number
60 * - slot number
61 */
62 unsigned int dir, dst_irq, ack_irq;
63 unsigned int slot;
64
65 struct hi6220_mbox *parent;
66 };
67
68 struct hi6220_mbox {
69 struct device *dev;
70
71 int irq;
72
73 /* flag of enabling tx's irq mode */
74 bool tx_irq_mode;
75
76 /* region for ipc event */
77 void __iomem *ipc;
78
79 /* region for mailbox */
80 void __iomem *base;
81
82 unsigned int chan_num;
83 struct hi6220_mbox_chan *mchan;
84
85 void *irq_map_chan[MBOX_CHAN_MAX];
86 struct mbox_chan *chan;
87 struct mbox_controller controller;
88 };
89
mbox_set_state(struct hi6220_mbox * mbox,unsigned int slot,u32 val)90 static void mbox_set_state(struct hi6220_mbox *mbox,
91 unsigned int slot, u32 val)
92 {
93 u32 status;
94
95 status = readl(mbox->base + MBOX_MODE_REG(slot));
96 status = (status & ~MBOX_STATE_MASK) | val;
97 writel(status, mbox->base + MBOX_MODE_REG(slot));
98 }
99
mbox_set_mode(struct hi6220_mbox * mbox,unsigned int slot,u32 val)100 static void mbox_set_mode(struct hi6220_mbox *mbox,
101 unsigned int slot, u32 val)
102 {
103 u32 mode;
104
105 mode = readl(mbox->base + MBOX_MODE_REG(slot));
106 mode = (mode & ~MBOX_ACK_CONFIG_MASK) | val;
107 writel(mode, mbox->base + MBOX_MODE_REG(slot));
108 }
109
hi6220_mbox_last_tx_done(struct mbox_chan * chan)110 static bool hi6220_mbox_last_tx_done(struct mbox_chan *chan)
111 {
112 struct hi6220_mbox_chan *mchan = chan->con_priv;
113 struct hi6220_mbox *mbox = mchan->parent;
114 u32 state;
115
116 /* Only set idle state for polling mode */
117 BUG_ON(mbox->tx_irq_mode);
118
119 state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
120 return ((state & MBOX_STATE_MASK) == MBOX_STATE_IDLE);
121 }
122
hi6220_mbox_send_data(struct mbox_chan * chan,void * msg)123 static int hi6220_mbox_send_data(struct mbox_chan *chan, void *msg)
124 {
125 struct hi6220_mbox_chan *mchan = chan->con_priv;
126 struct hi6220_mbox *mbox = mchan->parent;
127 unsigned int slot = mchan->slot;
128 u32 *buf = msg;
129 int i;
130
131 /* indicate as a TX channel */
132 mchan->dir = MBOX_TX;
133
134 mbox_set_state(mbox, slot, MBOX_STATE_TX);
135
136 if (mbox->tx_irq_mode)
137 mbox_set_mode(mbox, slot, MBOX_ACK_IRQ);
138 else
139 mbox_set_mode(mbox, slot, MBOX_ACK_AUTOMATIC);
140
141 for (i = 0; i < MBOX_MSG_LEN; i++)
142 writel(buf[i], mbox->base + MBOX_DATA_REG(slot) + i * 4);
143
144 /* trigger remote request */
145 writel(BIT(mchan->dst_irq), DST_INT_RAW_REG(mbox->ipc));
146 return 0;
147 }
148
hi6220_mbox_interrupt(int irq,void * p)149 static irqreturn_t hi6220_mbox_interrupt(int irq, void *p)
150 {
151 struct hi6220_mbox *mbox = p;
152 struct hi6220_mbox_chan *mchan;
153 struct mbox_chan *chan;
154 unsigned int state, intr_bit, i;
155 u32 msg[MBOX_MSG_LEN];
156
157 state = readl(ACK_INT_STAT_REG(mbox->ipc));
158 if (!state) {
159 dev_warn(mbox->dev, "%s: spurious interrupt\n",
160 __func__);
161 return IRQ_HANDLED;
162 }
163
164 while (state) {
165 intr_bit = __ffs(state);
166 state &= (state - 1);
167
168 chan = mbox->irq_map_chan[intr_bit];
169 if (!chan) {
170 dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
171 __func__, intr_bit);
172 continue;
173 }
174
175 mchan = chan->con_priv;
176 if (mchan->dir == MBOX_TX)
177 mbox_chan_txdone(chan, 0);
178 else {
179 for (i = 0; i < MBOX_MSG_LEN; i++)
180 msg[i] = readl(mbox->base +
181 MBOX_DATA_REG(mchan->slot) + i * 4);
182
183 mbox_chan_received_data(chan, (void *)msg);
184 }
185
186 /* clear IRQ source */
187 writel(BIT(mchan->ack_irq), ACK_INT_CLR_REG(mbox->ipc));
188 mbox_set_state(mbox, mchan->slot, MBOX_STATE_IDLE);
189 }
190
191 return IRQ_HANDLED;
192 }
193
hi6220_mbox_startup(struct mbox_chan * chan)194 static int hi6220_mbox_startup(struct mbox_chan *chan)
195 {
196 struct hi6220_mbox_chan *mchan = chan->con_priv;
197 struct hi6220_mbox *mbox = mchan->parent;
198
199 mchan->dir = 0;
200
201 /* enable interrupt */
202 writel(BIT(mchan->ack_irq), ACK_INT_ENA_REG(mbox->ipc));
203 return 0;
204 }
205
hi6220_mbox_shutdown(struct mbox_chan * chan)206 static void hi6220_mbox_shutdown(struct mbox_chan *chan)
207 {
208 struct hi6220_mbox_chan *mchan = chan->con_priv;
209 struct hi6220_mbox *mbox = mchan->parent;
210
211 /* disable interrupt */
212 writel(BIT(mchan->ack_irq), ACK_INT_DIS_REG(mbox->ipc));
213 mbox->irq_map_chan[mchan->ack_irq] = NULL;
214 }
215
216 static const struct mbox_chan_ops hi6220_mbox_ops = {
217 .send_data = hi6220_mbox_send_data,
218 .startup = hi6220_mbox_startup,
219 .shutdown = hi6220_mbox_shutdown,
220 .last_tx_done = hi6220_mbox_last_tx_done,
221 };
222
hi6220_mbox_xlate(struct mbox_controller * controller,const struct of_phandle_args * spec)223 static struct mbox_chan *hi6220_mbox_xlate(struct mbox_controller *controller,
224 const struct of_phandle_args *spec)
225 {
226 struct hi6220_mbox *mbox = dev_get_drvdata(controller->dev);
227 struct hi6220_mbox_chan *mchan;
228 struct mbox_chan *chan;
229 unsigned int i = spec->args[0];
230 unsigned int dst_irq = spec->args[1];
231 unsigned int ack_irq = spec->args[2];
232
233 /* Bounds checking */
234 if (i >= mbox->chan_num || dst_irq >= mbox->chan_num ||
235 ack_irq >= mbox->chan_num) {
236 dev_err(mbox->dev,
237 "Invalid channel idx %d dst_irq %d ack_irq %d\n",
238 i, dst_irq, ack_irq);
239 return ERR_PTR(-EINVAL);
240 }
241
242 /* Is requested channel free? */
243 chan = &mbox->chan[i];
244 if (mbox->irq_map_chan[ack_irq] == (void *)chan) {
245 dev_err(mbox->dev, "Channel in use\n");
246 return ERR_PTR(-EBUSY);
247 }
248
249 mchan = chan->con_priv;
250 mchan->dst_irq = dst_irq;
251 mchan->ack_irq = ack_irq;
252
253 mbox->irq_map_chan[ack_irq] = (void *)chan;
254 return chan;
255 }
256
257 static const struct of_device_id hi6220_mbox_of_match[] = {
258 { .compatible = "hisilicon,hi6220-mbox", },
259 {},
260 };
261 MODULE_DEVICE_TABLE(of, hi6220_mbox_of_match);
262
hi6220_mbox_probe(struct platform_device * pdev)263 static int hi6220_mbox_probe(struct platform_device *pdev)
264 {
265 struct device_node *node = pdev->dev.of_node;
266 struct device *dev = &pdev->dev;
267 struct hi6220_mbox *mbox;
268 int i, err;
269
270 mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
271 if (!mbox)
272 return -ENOMEM;
273
274 mbox->dev = dev;
275 mbox->chan_num = MBOX_CHAN_MAX;
276 mbox->mchan = devm_kcalloc(dev,
277 mbox->chan_num, sizeof(*mbox->mchan), GFP_KERNEL);
278 if (!mbox->mchan)
279 return -ENOMEM;
280
281 mbox->chan = devm_kcalloc(dev,
282 mbox->chan_num, sizeof(*mbox->chan), GFP_KERNEL);
283 if (!mbox->chan)
284 return -ENOMEM;
285
286 mbox->irq = platform_get_irq(pdev, 0);
287 if (mbox->irq < 0)
288 return mbox->irq;
289
290 mbox->ipc = devm_platform_ioremap_resource(pdev, 0);
291 if (IS_ERR(mbox->ipc)) {
292 dev_err(dev, "ioremap ipc failed\n");
293 return PTR_ERR(mbox->ipc);
294 }
295
296 mbox->base = devm_platform_ioremap_resource(pdev, 1);
297 if (IS_ERR(mbox->base)) {
298 dev_err(dev, "ioremap buffer failed\n");
299 return PTR_ERR(mbox->base);
300 }
301
302 err = devm_request_irq(dev, mbox->irq, hi6220_mbox_interrupt, 0,
303 dev_name(dev), mbox);
304 if (err) {
305 dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
306 err);
307 return -ENODEV;
308 }
309
310 mbox->controller.dev = dev;
311 mbox->controller.chans = &mbox->chan[0];
312 mbox->controller.num_chans = mbox->chan_num;
313 mbox->controller.ops = &hi6220_mbox_ops;
314 mbox->controller.of_xlate = hi6220_mbox_xlate;
315
316 for (i = 0; i < mbox->chan_num; i++) {
317 mbox->chan[i].con_priv = &mbox->mchan[i];
318 mbox->irq_map_chan[i] = NULL;
319
320 mbox->mchan[i].parent = mbox;
321 mbox->mchan[i].slot = i;
322 }
323
324 /* mask and clear all interrupt vectors */
325 writel(0x0, ACK_INT_MSK_REG(mbox->ipc));
326 writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));
327
328 /* use interrupt for tx's ack */
329 mbox->tx_irq_mode = !of_property_read_bool(node, "hi6220,mbox-tx-noirq");
330
331 if (mbox->tx_irq_mode)
332 mbox->controller.txdone_irq = true;
333 else {
334 mbox->controller.txdone_poll = true;
335 mbox->controller.txpoll_period = 5;
336 }
337
338 err = devm_mbox_controller_register(dev, &mbox->controller);
339 if (err) {
340 dev_err(dev, "Failed to register mailbox %d\n", err);
341 return err;
342 }
343
344 platform_set_drvdata(pdev, mbox);
345 dev_info(dev, "Mailbox enabled\n");
346 return 0;
347 }
348
349 static struct platform_driver hi6220_mbox_driver = {
350 .driver = {
351 .name = "hi6220-mbox",
352 .of_match_table = hi6220_mbox_of_match,
353 },
354 .probe = hi6220_mbox_probe,
355 };
356
hi6220_mbox_init(void)357 static int __init hi6220_mbox_init(void)
358 {
359 return platform_driver_register(&hi6220_mbox_driver);
360 }
361 core_initcall(hi6220_mbox_init);
362
hi6220_mbox_exit(void)363 static void __exit hi6220_mbox_exit(void)
364 {
365 platform_driver_unregister(&hi6220_mbox_driver);
366 }
367 module_exit(hi6220_mbox_exit);
368
369 MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
370 MODULE_DESCRIPTION("Hi6220 mailbox driver");
371 MODULE_LICENSE("GPL v2");
372